A very area-efficient type of surface mounted package which is increasing in popularity is a ball grid array package 10, illustrated in FIG. 1. Package 10 contains an integrated circuit having its pads electrically connected to respective ones of conductive solder balls 12 distributed on the bottom surface of package 10 in an array. A printed circuit board 14 has formed on its surface a corresponding array of conductive pads 16 which align with the array of solder balls 12. Conductive traces (not shown) on the printed circuit board 14 lead from each of the pads 16 to other circuitry on board 14. To mount package 10 to board 14, package 10 is positioned on top of board 14, and the resulting structure is heated until solder balls 12 melt and fuse to pads 16.
Ball grid array packages provide a high density of terminals at a very low cost. Also, by not having any pins extending from the package, there is no risk of bending any leads and destroying the product.
For a designer to test a circuit board which utilizes a ball grid array package, the designer must first electrically connect the solder balls on the ball grid array package to the printed circuit board. This typically entails fusing the solder balls to the printed circuit board, hence, preventing that package from being used again on a different board. Such ball grid array packages may be relatively expensive, thus, adding to the development cost of the printed circuit board.
What is needed is an adapter for a ball grid array package which electrically connects a ball grid array package to a printed circuit board without requiring the solder balls on the ball grid array package to be fused to the board.